This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. The term non-suicidal self-injury (NSSI) has been applied to a wide range of behaviors that result in the damage of one's own body tissue in the absence of intent to die. Populations comprised of those suffering from genetic syndromes, such as Prader-Willi, and psychological disorders such as autism and normative populations have all demonstrated NSSI. The seriousness and prevalence of these behaviors has led to a great deal of research both basic and clinical, investigating these populations. Much of that recent work has focused on the role of NSSI in emotion regulation. Specifically, it has been proposed that NSSI allow for a decrease or escape from aversive arousal associated with negative emotions such as fear or anxiety. This proposal outlines the development of an animal model of NSSI to shed light on the role of environmental stress and operant processes such as escape and avoidance in maintaining NSSI. The goal of this proposed research project is to develop an animal model of NSSI. In doing so, these specific goals will be addressed: (1) Determine if a fear evoking environment results in an increase in NSSI;(2) Determine if any increase in NSSI comes at the cost of a decrease in an effective and healthy behavior;(3) Determine which factors, such as the timing, regularity and predictability, of the environmental stressor, are most predictive of NSSI.